vocal cord dysfunction  





Vocal Cord dysfunction (VCD)



Vocal cord dysfunction often mimics asthma. VCD is characterized by episodic dyspnea and wheezing caused by intermittent paradoxical vocal cord adduction during inspiration (sometimes with abnormal adduction during expiration as well). The cause of VCD is not well understood, although some patients develop VCD in response to irritant triggers, such as fumes, cold air, and exercise. Although VCD is clearly distinct from asthma, it is often confused with asthma, leading to inappropriate medication of affected individuals with anti-asthma medications.

Asthma medications typically do little, if anything, to relieve symptoms if the patient has pure VCD. VCD should be considered in the differential of difficult-to-treat, atypical asthma patients.

It is important to note, however, that VCD and asthma may coexist and that VCD may complicate asthma management. Elite athletes, in particular, are prone to both exercise induced bronchospasm (EIB) and VCD, so careful workup is warranted for athletes who present with exercise-related breathlessness (Rundell and Spiering 2003).

During severe VCD episodes, respiratory distress may be severe and lead to intubation. Once the trachea is intubated, the wheezing and distress abate in VCD but not in asthma.

VCD can be difficult to diagnose. Variable flattening of the inspiratory flow loop on spirometry is strongly suggestive of the diagnosis, but abnormalities of the inspiratory loop may well be absent between episodes.

The diagnosis of VCD comes from indirect or direct vocal cord visualization during an episode, during which the abnormal adduction can be documented.
Therapy generally consists of speech therapy and relaxation techniques (Bucca et al. 1995; Christopher et al. 1983; Newman et al. 1995).



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Last edited 18-6-2009